Unused code for mastering chemistry. Bought because I thought I needed it for my chemistry course but it wasn't needed. I scratched it off but did not use the code. I paid 126.00 for this and the chemistry book and I only bought it for the code. The person at the book store told me I needed it for my course so I bought it and didn't need it after all. Before this is sold I will make sure it works for you. I don't want anyone to be out money but I would like my money back for this since I was told I needed it when I didn't. Call or text 763-9626 if interested :)